I think this a good article explaining why there is not enough evidence in the public linking the DNC hack to Russian secret service:

https://medium.com/@jeffreycarr/can-facts-slow-the-dnc-breac...

The IP-address (176.31.112.10) that links the DNC hack to the Bundestag hack is a machine in France (appearantly) controlled by a Pakistani hosting company. This article says the machine was closed because of abuse over a year ago. The material in the DNC hack is just one month old:

https://netzpolitik.org/2015/digital-attack-on-german-parlia...